The railroad industry employs a variety of freight railroad cars for transporting products. Many of these freight railroad cars (such as boxcars and auto-rack railroad cars) are enclosed to protect the products or vehicles being transported. Enclosed railroad cars generally include one or more sliding doors to provide access to the interior of the railroad cars. The doors are generally mounted on upper and lower tracks which are attached to the frames of the railroad cars. The doors have conventional door locks to alternatively maintain the doors in an open position or a closed position.
Most conventional railroad car door locks must be lubricated with a standard lubricant such as grease. The lubricants such as grease attract particles and other materials, generally creating a dirty environment and sometimes causing contamination in the interior of the railroad cars.
This problem is especially undesirable in auto-rack railroad cars which transport newly manufactured vehicles, including automobiles, vans, and trucks, auto-rack railroad cars, known in the railroad industry as auto-rack cars, often travel thousands of miles through varying terrain. The typical auto-rack car is compartmented, having a frame, one, two or three decks or floors, two side walls, a roof, and a pair of doors at each end of the auto-rack car. The doors protect the auto-rack car from illegal or unauthorized entry and prevent theft or vandalism of the vehicles. The doors also prevent flying objects from entering the auto-rack car and damaging the vehicles. In transit, the doors on auto-rack cars are secured in the closed position. When the automobiles are being loaded or unloaded, the doors are secured in the open position. Examples of such doors for auto-rack cars are generally illustrated in U.S. Pat. Nos. 3,995,563 and 4,917,021.
Each door in an auto-rack car includes at least one door lock having a locking pin which engages a socket attached to the frame of the auto-rack car. The grease and dirt that builds up on these door locks often creates a dirty environment and can cause grease contamination inside the auto-rack cars. This is highly undesirable for the transport of newly manufactured vehicles because the grease and dirt can damage the finishes of the vehicles being transported. The grease also tends to drip or fall off the door locks onto the floors or door tracks of the auto-rack cars. Workers can step in this grease and then track the grease into the new vehicles being transported. Thus, the grease sometimes damages the interior carpeting in the new vehicles being transported.
The Association of American Railroads (“AAR”) requires that the railroad car door locks and rollers be lubricated or greased every twelve months or sooner if necessary. The AAR also requires that the date on which the door locks and rollers are lubricated or greased be painted on the inside of the auto-rack cars for tracking purposes. This requires extensive tracking procedures for this regular maintenance which increases the cost of operating the auto-rack cars and decreases the efficiency of the use of the auto-rack cars.
Accordingly, there is a continuing need for door locks for railroad cars, and in particular for auto-rack cars, which do not need to be lubricated on a regular basis and which eliminate grease contamination.